diff --git a/core/artwork/artwork.go b/core/artwork/artwork.go
index 6cf466c64..218c4d665 100644
--- a/core/artwork/artwork.go
+++ b/core/artwork/artwork.go
@@ -51,9 +51,9 @@ func NewArtwork(ds model.DataStore, cache cache.FileCache, store *ImageStore, ff
 	return &service{ds: ds, cache: cache, store: store, ffmpeg: ffm}
 }
 
-// EntityExists reports whether the entity an artwork id points at is still there: state rows
+// entityExists reports whether the entity an artwork id points at is still there: state rows
 // outlive a deleted entity until the next prune, so a servable row is not evidence of its owner.
-func EntityExists(ctx context.Context, ds model.DataStore, artID model.ArtworkID) bool {
+func entityExists(ctx context.Context, ds model.DataStore, artID model.ArtworkID) bool {
 	var found bool
 	var err error
 	switch artID.Kind {
@@ -172,7 +172,7 @@ func (s *service) serveSource(ctx context.Context, key, hash string, lastUpdate
 // cancelled request is not: it must not enqueue a re-resolution.
 func (s *service) serveHash(ctx context.Context, artID model.ArtworkID, ia *model.ItemArtwork, size int, square bool) (*Image, error) {
 	// Only this path can hand back a deleted entity's bytes; the others load their entity anyway.
-	if !EntityExists(ctx, s.ds, artID) {
+	if !entityExists(ctx, s.ds, artID) {
 		return nil, ErrUnavailable
 	}
 	art, err := s.ds.Artwork(ctx).GetImage(ia.Hash)
@@ -366,13 +366,6 @@ func placeholderImage(kind model.Kind) *Image {
 	return &Image{ReadCloser: r, Placeholder: true}
 }
 
-// PlaceholderFor returns the kind-appropriate placeholder for an artwork id, for callers that
-// must not consult persisted state (e.g. an access-control denial).
-func PlaceholderFor(id string) *Image {
-	artID, _ := model.ParseArtworkID(id)
-	return placeholderImage(artID.Kind)
-}
-
 type coverArtIDGetter interface {
 	CoverArtID() model.ArtworkID
 }
diff --git a/core/artwork/artwork_test.go b/core/artwork/artwork_test.go
index 59429d8b4..c58a0fe4e 100644
--- a/core/artwork/artwork_test.go
+++ b/core/artwork/artwork_test.go
@@ -507,7 +507,7 @@ var _ = Describe("EntityExists", func() {
 
 	DescribeTable("reports whether the owning entity is still there",
 		func(id string, expected bool) {
-			Expect(EntityExists(ctx, ds, model.MustParseArtworkID(id))).To(Equal(expected))
+			Expect(entityExists(ctx, ds, model.MustParseArtworkID(id))).To(Equal(expected))
 		},
 		Entry("existing album", "al-al1", true),
 		Entry("deleted album", "al-gone", false),
diff --git a/core/artwork/blurhash/blurhash.go b/core/artwork/blurhash/blurhash.go
index 5dfd8754f..405d7e714 100644
--- a/core/artwork/blurhash/blurhash.go
+++ b/core/artwork/blurhash/blurhash.go
@@ -81,7 +81,7 @@ func Encode(img image.Image) (string, error) {
 	}
 
 	var sb strings.Builder
-	sb.WriteString(Encode83((xComp-1)+(yComp-1)*9, 1))
+	sb.WriteString(encode83((xComp-1)+(yComp-1)*9, 1))
 
 	// Derived counts are at least 1x9, so there is always at least one AC factor.
 	ac := factors[1:]
@@ -91,12 +91,12 @@ func Encode(img image.Image) (string, error) {
 	}
 	quantMax := int(max(0, min(82, math.Floor(actualMax*166-0.5))))
 	maxVal := float64(quantMax+1) / 166
-	sb.WriteString(Encode83(quantMax, 1))
+	sb.WriteString(encode83(quantMax, 1))
 
 	dc := factors[0]
-	sb.WriteString(Encode83(linearToSRGB(dc[0])<<16|linearToSRGB(dc[1])<<8|linearToSRGB(dc[2]), 4))
+	sb.WriteString(encode83(linearToSRGB(dc[0])<<16|linearToSRGB(dc[1])<<8|linearToSRGB(dc[2]), 4))
 	for _, f := range ac {
-		sb.WriteString(Encode83(quantAC(f[0], maxVal)*19*19+quantAC(f[1], maxVal)*19+quantAC(f[2], maxVal), 2))
+		sb.WriteString(encode83(quantAC(f[0], maxVal)*19*19+quantAC(f[1], maxVal)*19+quantAC(f[2], maxVal), 2))
 	}
 	return sb.String(), nil
 }
@@ -156,8 +156,8 @@ func linearToSRGB(v float64) int {
 	return int((1.055*math.Pow(v, 1/2.4)-0.055)*255 + 0.5)
 }
 
-// Encode83 encodes value as a fixed-width, big-endian base83 string of the given length.
-func Encode83(value, length int) string {
+// encode83 encodes value as a fixed-width, big-endian base83 string of the given length.
+func encode83(value, length int) string {
 	b := make([]byte, length)
 	for i := length - 1; i >= 0; i-- {
 		b[i] = alphabet[value%83]